Annex A. Statistical annex

A.1. Inflows of foreign population into OECD countries

B.1. Inflows of foreign population by nationality

A.2. Outflows of foreign population from selected OECD countries

Metadata relative to Tables A.1, B.1. and A.2. Inflows and outflows of foreign population

A.3. Inflows of asylum seekers into OECD countries

B.3. Inflows of asylum seekers by nationality

Metadata relative to Tables A.3. and B.3. Inflows of asylum seekers

A.4. Stocks of foreign-born population in OECD countries

B.4. Stocks of foreign-born population by country of birth

Metadata relative to Tables A.4. and B.4. Stocks of foreign-born population

A.5. Stocks of foreign population by nationality in OECD countries

B.5. Stocks of foreign population by nationality

Metadata relative to Tables A.5. and B.5. Stocks of foreign population

A.6. Acquisitions of nationality in OECD countries

B.6. Acquisitions of nationality by country of former nationality

Metadata relative to Tables A.6. and B.6. Acquisitions of nationality

Most of the data published in this annex have been provided by national correspondents of the OECD Expert Group on Migration appointed by the OECD Secretariat with the approval of the authorities of member countries. Consequently, these data are not necessarily based on common definitions. Countries under review in this annex are OECD countries for which data are available. The OECD Expert Group on Migration has no authority to impose changes in data collection procedures. It is an observatory which, by its very nature, has to use existing statistics. However, it does play an active role in suggesting what it considers to be essential improvements in data collection and makes every effort to present consistent and well-documented statistics.

The purpose of this annex is to describe the “immigrant” population (generally the foreign-born population). The information gathered concerns the flows and stocks of the total immigrant population as well as the acquisition of nationality. These data have not been standardised and are therefore not fully comparable across countries. In particular, the criteria for registering persons in population registers and the conditions for granting residence permits, for example, vary across countries, which means that measurements may differ greatly even if the same type of source is being used.

In addition to the problem of the comparability of statistics, there is the difficulty of the very partial coverage of unauthorised migrants. Part of this population may be counted in censuses. Regularisation programmes, when they exist, make it possible to identify and enumerate a far from negligible fraction of unauthorised immigrants after the fact. In terms of measurement, this makes it possible to better measure the volume of the foreign-born population at a given time, even if it is not always possible to determine the year these immigrants entered the country.

Each series in the annex is preceded by an explanatory note concerning the data presented. A summary table then follows (series A, giving the total for each destination country), and finally the tables by nationality or country of birth, as the case may be (series B). At the end of each series, a table provides the sources and notes for the data presented in the tables for each country.

The tables provide annual series covering the period 2010-20 or 2011-21.

  • The series A tables are presented in alphabetical order by the name of the country. In the other tables, nationalities or countries of birth are ranked by decreasing order of frequency for the last year available.

  • In the tables by country of origin (series B), only the 15 main countries are shown. “Other countries” is a residual calculated as the difference between the total foreign or foreign-born population and the sum for all countries indicated in the table. For some countries, data are not available for all years and this is reflected in the residual entry of “Other countries”. This must be borne in mind when interpreting changes in this category.

  • There is no table by nationality for the series on outflows of the foreign population (series A.2). These statistics, as well as data by gender, are available online (

  • The rounding of data cells may cause totals to differ slightly from the sum of the component cells.

  • The symbol “..” used in the tables means that the data are not available.

  • Figures in italic are estimated by the Secretariat.